Pseudoscience Dictionary: Exorcism

Pseudoscience: Consists of statements, beliefs, or practices that are claimed to be both scientific and factual but are incompatible with the scientific method (unproven, not testable, or opposed to the consensus of traditional science).

Exorcism

Definition: Exorcism is a religious or spiritual practice intended to expel demons, evil spirits, or other supernatural entities believed to possess or influence a person. The practice exists in various religious traditions and commonly involves prayers, religious commands, rituals, or blessings. Proponents sometimes claim that demonic possession causes unexplained behavior, seizures, hallucinations, personality changes, or mental illness and that exorcism can eliminate these conditions. While exorcism is a legitimate expression of religious belief for many practitioners, claims that supernatural possession causes medical or psychiatric disorders and can be cured through exorcism lack credible scientific evidence.

Reasoning: There is no scientifically established evidence that demonic possession causes mental or physical illness or that exorcism is an effective medical treatment. According to the World Health Organization’s International Classification of Diseases (ICD-11), possession trance disorder is classified as a dissociative disorder involving altered consciousness and the experience of being controlled by an external identity. This clinical classification does not establish supernatural possession as the cause. Further, a 1994 study published in the British Journal of Medical Psychology examined 343 psychiatric patients in Switzerland and found that 104 had sought help through exorcism or similar religious rituals. Although some participants described subjective benefits, the study found no improvement in psychiatric symptoms associated with these practices. It also identified negative outcomes when medical treatment was excluded or coercive exorcisms were performed. Similarly, a 2022 peer-reviewed study published in Frontiers in Psychiatry documented how beliefs about supernatural possession could discourage individuals from seeking appropriate psychiatric treatment. Finally, a 2025 review published in the Irish Journal of Psychological Medicine emphasized the importance of distinguishing spiritual beliefs from psychiatric disorders and warned about the potential risks of exorcism interfering with conventional treatment.

More Information

• Belief in Demons and Exorcism in Psychiatric Patients in Switzerland – British Journal of Medical Psychology
• Trapped Between Theological and Medical Notions of Possession – Frontiers in Psychiatry
• See No Evil, Hear No Evil? The Role of Psychiatry in Exorcism – Irish Journal of Psychological Medicine

Conclusion: Exorcism is a religious practice rather than a scientifically validated medical treatment. There is no credible scientific evidence that demonic possession causes illness or that exorcism cures physical or psychiatric disorders. While voluntary religious rituals may provide spiritual comfort, treating medical symptoms as supernatural possession can delay proper diagnosis and treatment. Coercive or physically abusive exorcisms can also cause serious harm.